This section provides background information related to the present disclosure which is not necessarily prior art.
Lithium-ion and related batteries generally operate by reversibly transporting lithium ions between negative and positive electrodes. The basic unit of a lithium-ion battery is an individual cell that includes an anode, a cathode, and a non-aqueous electrolyte. To prevent physical contact (electron-conducting contact) between the anode and cathode, which would result in an internal short circuit, a separator may be positioned between the electrodes. The separator, commonly a polyolefin polymer, may be microporous and contain small pores that are filled with the electrolyte to provide pathways for the passage of lithium ions from one electrode to the other. The separator is an expensive component. In order to reduce the battery cost, various attempts have been made at directly forming a separator on an electrode to fabricate an integral separator/electrode However, separator coatings formed this way are smaller in size or have the same size as the electrode substrate, which can cause an internal battery short at the electrode edges.
Thus, there remains a need for a continuous process to form separator coating layers larger in size than the electrode substrate.